From the Archives 1994: Climate study finds warming real

25 years ago, the most comprehensive study of climate change conducted anywhere in the world examined data for Australia and the South Pacific and found "the warming is real".

By Leigh Dayton

October 10, 2019 — 6.54am

First published in the Herald, 11 October 1994.

WE'RE GETTING WARMER, STUDY REVEALS

By Leigh Dayton, Herald's Science Writer

It's a fact. Australia and its South Pacific neighbours are getting warmer

The most comprehensive study of climate change conducted anywhere in the world concludes that the average temperature in the South Pacific region rose by between 0.4 and 0.8 degrees Celsius between 1951 and 1993.

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The warming is real

Dr Neville Nicholls, leader of the climate research group at the Bureau of Meteorology in Melbourne

Data from the turn of the century shows that temperatures in Australia rose by between 0.1 and 1.0 degrees.

"The warming is real," meteorologist Dr Neville Nicholls, leader of the climate research group at the Bureau of Meteorology in Melbourne, said yesterday. Dr Nicholls is one of 10 scientists from seven leading research institutions in Australia and New Zealand who participated in the ground-breaking study.

The findings - which were presented yesterday at the Australian-New Zealand Conference on Climate Change in Wellington - are more dramatic than the rises estimated by the Intergovernmental Panel on Climate Change (IPCC). IPCC figures suggested that land and sea surface temperatures had risen by 0.3 to 0.6 degrees over the past century.

The regional experts also reported on changes to sea level, rainfall and cloud cover in Oceania. These variables, which are closely tied to warming, confirmed the conclusion that temperatures are on the rise.

The team found that the sea level was rising by 2 millimetres a year. The conclusion was based on records going back 50 years in Australia and more than 75 years in New Zealand. Long-term data from Pacific islands was less reliable, but modern tide gauges there were excellent, the scientists said, and provided data which matched that from Australia and New Zealand.

Shifts in rainfall patterns across the region are less straightforward. Generally, rain was increasing north of a region climatologists call the South Pacific Convergence Zone and decreasing south-west of the zone, the team discovered.

Warming of Oceania graphic, published in the Herald, 11 October 1994Credit:

Long-term data from Australia showed that despite a trend to lower rainfall south-west of the zone, summer rainfall on the east coast increased "abruptly"after 1950, the report claimed. In south-western Australia, though, the scientists found a "smooth trend to lower winter precipitation".

The rainfall findings were more complicated than those for temperature and sea level, in part, because of the "tremendous" variability in rainfall from year to year, Dr Nicholls noted. He pointed to El Nino as a major cause of variability.

El Nino is a natural fluctuation in the circulation of the currents and atmosphere over the Pacific Ocean. During a so-called El Nino year, less rain falls on Australia, while more rain falls on South America. Scientists are still trying to unravel the links between climate change and El Ninos.

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The amount of cloud cover in Oceania increased by 5 per cent as the temperatures rose, the

Along with the Bureau of Meteorology, Australian team members are from the CSIRO Division of Atmospheric Research in Melbourne, the Co-operative Research Centre for Antarctic and Southern Ocean Environment in Hobart, the Australian National University in Canberra and the University of Melbourne.

New Zealand contributors are based at the National Institute of Water and Atmospheric Research in Auckland and the University of Otago in Dunedin.